package com.teamin.utils;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.*;

public class WXAESUtils {
    public static boolean initialized = false;  
    /** 
     * AES解密 
     * @param content 密文 
     * @return 
     * @throws InvalidAlgorithmParameterException 
     * @throws NoSuchProviderException 
     */  
    public byte[] decrypt(byte[] content, byte[] keyByte, byte[] ivByte) throws InvalidAlgorithmParameterException {  
        initialize();  
        try {  
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");  
            Key sKeySpec = new SecretKeySpec(keyByte, "AES");  
            cipher.init(Cipher.DECRYPT_MODE, sKeySpec, generateIV(ivByte));// 初始化  
            byte[] result = cipher.doFinal(content);  
            return result;  
        } catch (NoSuchAlgorithmException e) {  
            e.printStackTrace();  
        } catch (NoSuchPaddingException e) {  
            e.printStackTrace();  
        } catch (InvalidKeyException e) {  
            e.printStackTrace();  
        } catch (IllegalBlockSizeException e) {  
            e.printStackTrace();  
        } catch (BadPaddingException e) {  
            e.printStackTrace();  
        } catch (NoSuchProviderException e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
        } catch (Exception e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
        }  
        return null;  
    }  
    public static void initialize(){  
        if (initialized) return;  
        Security.addProvider(new BouncyCastleProvider());  
        initialized = true;  
    }  
    //生成iv  
    public static AlgorithmParameters generateIV(byte[] iv) throws Exception{  
        AlgorithmParameters params = AlgorithmParameters.getInstance("AES");  
        params.init(new IvParameterSpec(iv));  
        return params;  
    }  
}